Depth Of Field - Contax 167MT Manual

When the lens is focused on a subiect, not only the
subiect itself, but also a certain zone in front of and
behind it will turn out sharp in the picture. Ihis rs
called the depth of field of a lens and it varies as
follows:
@ The smaller the aperture, the wider the depth of field,
and vice versa.
@ The longer the subject distance, the wider the depth of
field, and vice versa.
@ The zone of sharpness behind the point on which the
lens is focused is wider than that in front of it. In the case
of different lenses, lenses with a shorter facal length have
a wider depth of field than those with a longer focal
length.